The present invention relates to a single-mode laser, in particular in the form of a diode-pumped solid state laser, whereby this laser can also be used as a frequency-doubled laser, optionally for single-mode operation or multimode operation.
For a laser to have single-mode operation, i.e. operation involving only the basic transversal mode and a longitudinal mode in accordance with the wavelength of the active laser medium, the resonator must meet certain criteria. To limit the transversal modes to the basic mode one can use mode screens or adapt the volume of the pumped light to the volume of the basic mode of the resonator.
The invention is based on the problem of providing a laser characterized by particularly stable single-mode operation and designed as a frequency-doubled laser in a special embodiment, also in multimode operation.